<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>引入文件</title>
  <script src="../jquery/jquery-3.3.1.min.js"></script>
  <script>
      //js 加载函数  onload
    $(function (){

      alert($("#ele_div").html());
    })
  </script>
</head>
<body>
<div id="ele_div">
  何以解忧：唯有干饭
</div>
</body>
</html>